Desmoid and fibroma tumors differently respond to TGFβ1 stimulus and ECM macromolecule accumulation

Desmoid and fibroma tumours are characterized by cell proliferation, glycosaminoglycan and collagen fibre accumulation, high levels of transforming growth factor β1 (TGFβ1) and different patterns of tissue infiltration. TGFβ1 is related to extracellular matrix (ECM) composition which, in turn, regulates cell functions and cell migration. In this study we report changes in cell proliferation, glycosaminoglycan (GAG) and collagen synthesis, TGFβ1 mRNA expression and fibronectin levels in normal, desmoid and fibroma fibroblast cultures before and after TGFβ1 stimulation. Our data showed cell proliferation, GAG and collagen synthesis, transforming growth factor β1 mRNA expression and fibronectin levels were significantly higher in desmoid than in fibroma cultures. TGFβ1 treatment had no effect on cell proliferation, but increased TGFβ1 mRNA expression, GAG, fibronectin and collagen synthesis in desmoid and fibroma fibroblasts. Its effects were more marked in desmoid cells. Fibronectin favours cell migration, while changes in GAG composition alter cell behaviour and ECM organization. In conclusion our data suggest that the different patterns of infiltration in desmoid and fibroma tumours are due to changes in ECM components and cell–ECM interactions which can be ascribed to altered TGFβ1 mRNA expression and TGFβ1 activity.